The data analysis interview asks you how you would predict some number. First you go through data ideation (if you could gather any reasonable data, what would you want?), then you talk about how you would go about engineering features and cleaning your data, then you talk about what kind of model you would use and why. They really drill into your answers, and you are likely not going to pass if you don't have a lot of experience in predictive modeling. Watch the mock interview video on their website for an easy example of what this is like.